Responsive Background Image Swapping

gistfile1.html

<div 
    class="featured-media featured-media--full-height featured-media--align-center clearfix background-image-swap"
    style="background-image:url('/sites/default/files/styles/600x400/public/2017-10/maxresdefault.jpg?itok=E5qxr2Dx');"
    data-src-set="
            /sites/default/files/styles/2400x1600/public/2017-10/maxresdefault.jpg?itok=F7dLgnBM|all and (min-width: 1800px)|
            /sites/default/files/styles/1800x1200/public/2017-10/maxresdefault.jpg?itok=iiH_TyjT|all and (min-width: 1201px) and (max-width: 1799px)|
            /sites/default/files/styles/1200x800/public/2017-10/maxresdefault.jpg?itok=a5RsL9YX|all and (min-width: 961px) and (max-width: 1200px)|
            /sites/default/files/styles/900x600/public/2017-10/maxresdefault.jpg?itok=tlhEVdgF|all and (min-width: 601px) and (max-width: 960px)|
            /sites/default/files/styles/600x400/public/2017-10/maxresdefault.jpg?itok=E5qxr2Dx||
    "
 >
</div>
        
        
<script type="text/javascript">
(function swapBackgroundImages(){
    jQuery('.background-image-swap').each(function(){
        var imageStyles = jQuery(this).attr('data-src-set').split('|');
        for(i=0;i<imageStyles.length;i++){
            if(isEven(i)){
                var query = Modernizr.mq(imageStyles[i+1].trim());
                if (query) {
                    console.log(imageStyles[i+1].trim());
                    console.log(imageStyles[i].trim());
                    //console.log(this);
                    jQuery(this).attr('style',"background-image:url('"+imageStyles[i].trim()+"');");
                    break;
                }
            }
        }
    });
})();

function isEven(n) {
    n = Number(n);
    return n === 0 || !!(n && !(n%2));
}
    
</script>